explicit abstract Form class

diff --git a/ipf/form.php b/ipf/form.php
index 3d4e93d8b5ab015a1195d0455638316e24c6e100..3df7f72737e0552c4dbb29e22ed87f1081333490 100644 (file)
--- a/ipf/form.php
+++ b/ipf/form.php
@@ -1,6 +1,6 @@
 <?php
 
-class IPF_Form implements Iterator
+abstract class IPF_Form implements Iterator
 {
     public $fields = array();
     public $field_groups = array();
@@ -30,10 +30,7 @@ class IPF_Form implements Iterator
         $this->f = new IPF_Form_FieldProxy($this);
     }
 
-    function initFields($extra=array())
-    {
-        throw new IPF_Exception('Definition of the fields not implemented.');
-    }
+    abstract protected function initFields($extra=array());
 
     function addPrefix($field_name)
     {